CATH Classification

Domain Context

CATH Clusters

Superfamily Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Functional Family Proteasome subunit alpha type-6

Enzyme Information

3.4.25.1
Proteasome endopeptidase complex.
based on mapping to UniProt P40302
Cleavage of peptide bonds with very broad specificity.
-!- A 20-S protein composed of 28 subunits arranged in four rings of seven. -!- The outer rings are composed of alpha subunits, but the beta subunits forming the inner rings are responsible for peptidase activity. -!- In eukaryotic organisms there are up to seven different types of beta subunits, three of which may carry the N-terminal threonine residues that are the nucleophiles in catalysis, and show different specificities. -!- The molecule is barrel-shaped, and the active sites are on the inner surfaces. -!- Terminal apertures restrict access of substrates to the active sites. -!- Inhibited by mercurial reagents and some inhibitors of serine endopeptidases. -!- Belongs to peptidase family T1. -!- Formerly EC 3.4.22.21, EC 3.4.24.5 and EC 3.4.99.46.

UniProtKB Entries (1)

P22141
PSB4_YEAST
Saccharomyces cerevisiae S288C
Proteasome subunit beta type-4

PDB Structure

PDB 4Y6A
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Systematic Analyses of Substrate Preferences of 20S Proteasomes Using Peptidic Epoxyketone Inhibitors.
Huber, E.M., de Bruin, G., Heinemeyer, W., Paniagua Soriano, G., Overkleeft, H.S., Groll, M.
J.Am.Chem.Soc.